1. Technical Field
The present invention relates to a slide valve device for automatic surface pressure application, and more particularly, to a novel improvement for eliminating heavy physical work conducted under high temperature, stabilizing a surface pressure application force, and achieving compactification in a slide valve device constituted by a fixed plate, a slide plate, and a seal plate.
2. Description of the Related Art
Generally, the continuous casting facilities are provided with, as means for controlling outflow of a molten metal from a molten metal vessel, a slide valve device provided at a bottom portion of the molten metal vessel, for opening and closing an outflow port.
Examples of structures of the slide valve device include a toggle mechanism in which a surface pressure is manually applied and released. Further, as another example, there may be given a slide valve device having a two-layer structure (Japanese Patent Application No. 2004-327405), which is manufactured by the applicants of the present invention as illustrated in FIG. 12. That is, a fixed plate 3 is incorporated in a base frame 2 fixed to a bottom portion of a molten metal vessel 1, and a slide plate 5 and a shooting nozzle 6 are supported in a slide case 4 positioned below the fixed plate 3. By pushing and drawing the slide case 4 by means of a hydraulic or electrical actuator 7, a nozzle hole 3a of the fixed plate 3 and a nozzle hole 5a of the slide plate 5 are caused to match or mismatch with each other. As a result, control is performed for an outflow of a molten metal which flows downward from the molten metal vessel 1 through an insertion nozzle 8.
As illustrated in FIGS. 12 and 13, the slide case 4 is biased upward by using springs 12 through a pressing means in which rollers (movable bodies) 14 sliding on a support surface 13 are used, and the slide plate 5 is brought into contact with the fixed plate 3 with a predetermined pressing force. As a result, leakage of a molten metal and intrusion of air through the respective nozzle holes 3a and 5a of the fixed plate 3 and the slide plate 5 may be prevented. Further, as illustrated in FIG. 14, the slide case 4 having the rollers 14 is openable and closable through an intermediation of an axial support portion 15, and hence replacement of a fireproof material may be performed.
The pressing means in the slide valve device having a similar basic structure as described in the above structure is disclosed in JP 01-38592 B, for example.
Further, in the sliding nozzle device provided with a surface pressure application/release mechanism disclosed in JP 06-226430 A (not shown), application and release of the surface pressure to the elastic means may be achieved through a movement of the pressing member, and the application and release of the surface pressure and the opening/closing operation of the flow path may be achieved by means of independent driving mechanism.